Attachment D - Stormwater and Water Quality report

                                                                                Callaghan & Toth



4.4      MUSIC Modelling Results

The MUSIC modelling program has been used to investigate the performance of various
treatment options in the treatment train. MUSIC version 6.2.1 is the current version and capable
of incorporating rainwater re-use in the model. These features have been used in making
comparisons between different stormwater management systems for this report.


4.4.1 Water Quality Objectives

This model meets the pollution load reduction target as detailed in the State Planning Policy
2017 (Appendix 2: Table B). The following have been included in Appendix A.

                The treatment train effectiveness for the system.
                The MUSIC Version 6.2.1 Summary Report.

The information above indicates that the new carpark, carpark roof, footpaths, and associated
landscaping with the proposed stormwater treatment train will achieve reductions in pollutant
loads as detailed in Table 4.2 below.

         TABLE 4.2:         COMPARISON OF LOAD REDUCTIONS

             Parameter                       MUSIC            POLLUTANT LOAD
                                           REDUCTION             REDUCTION
                                            RESULT                TARGETS
                                                              (Source: SPP 2017)
             Flow                              1.4%
             Total Suspended Solids            84%                   80%
             Total Phosphorous                 60%                   60%
             Total Nitrogen                    45%                   45%
             Gross Pollutants >5mm             99%                   90%




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2001 Lower Mill Carpark Extension SWMP                                       February 2020